A plasma display panel (hereinafter simply referred to as “panel”) is a display device excellent in visibility and features a large size, thin and light weight screen.
An AC surface discharge panel, one of typical panels, comprises numbers of discharging cells formed between a front plate and a back plate confronting each other. The front plate comprises display electrode pairs each one of which pair is formed of a scan electrode and a sustain electrode, and the display electrode pairs are formed in parallel to each other on a front glass substrate. A dielectric layer and a protective layer are formed such that those two layers cover the display electrodes. The back plate comprises a plurality of data electrodes formed on a back glass substrate in parallel to each other, a dielectric layer covering the plurality of data electrodes, and a plurality of barrier ribs formed on the dielectric layer in parallel with the data electrodes. The dielectric layer has a phosphor layer on its surface, and the barrier ribs have phosphor layers on their lateral faces. The front plate confronts the back plate such that the display electrode pairs and the data electrodes form two-level crossings. The front plate and the back plate are sealed, and discharge gas is filled in a discharge space of the sealed body. In the foregoing panel, gas-discharge in respective discharge cells will generate ultraviolet rays, which then excite and emit the phosphors of respective colors, i.e. Red, Green and Blue, thereby displaying a gray scale.
The sub-field method is generally used as a method of driving the panel, this method divides one field period into a plurality of sub-fields, and combines some sub-fields emitting respectively for displaying a gradation. Each one of the sub-fields has an initializing period, an addressing period, and a sustaining period.
In the initializing period, every discharge cell carries out the initializing discharge all at once, so that hysteresis of wall electric charges with respect to each one of discharge cells is cancelled, and yet, wall electric charges necessary for an address operation coming next are formed. On top of that, the initializing period works to generate “priming” (exciting particles=initiating agent for discharge). In the addressing period, scan pulse voltages are sequentially applied to the scan electrodes, and address pulse voltages corresponding to video signals to be displayed are applied to the data electrodes, so that address-discharges are selectively generated between the scan electrodes and the data electrodes for forming selective wall electric charges. In the sustaining period following the addressing period, sustain pulse voltages are applied the given number of times between the scan electrodes and the sustain electrodes, so that the discharge cells, which have formed wall electric charges due to address discharge, selectively discharge and emit.
As discussed above, it is important to conduct the address discharges selectively in the addressing period in order to display a video correctly. However, there are several factors delaying the discharges, e.g. a high voltage cannot be used to an address pulse voltage due to constraints of the circuit structure, or the phosphor layer formed on the data electrodes make it difficult to conduct the address discharges. Thus the priming for steadily generating the address discharges becomes a crucial factor.
The priming generated by the discharges, however, decreases rapidly with the passage of time, so that the priming generated by the initial discharge becomes in short supply for the address discharge to be conducted long after the initial discharge. As a result, the discharge delays longer, which makes the address operation unstable and lowers the video quality, or an address time is set longer in order to make the address operation stable, so that the address operation resultantly takes too much time.
Unexamined Japanese Patent Publication No. H09-245627 discloses a panel and a method of driving the panel: a priming electrode is provided for generating the priming so that a discharge delay becomes shorter. This panel, however, tends to invite interference between discharge cells adjacent to each other. Particularly in the addressing period, the discharge of the discharge cells adjacent to each other produces some priming which sometimes causes an address error or an address defective. A margin in a driving voltage for the address operation becomes thus smaller.